Got married in Scotland. It is a beautiful place with fantastic people. I’d suggest you speak to the Scottish Dopers we have here.
Aside from that I’d just reinforce what previous posters have said- do not miss Edinburgh- it is an amazing and beautiful city. If you have the resources, try and get one of the local walking guides.
We always go in October- low season for the airlines and tourists numbers are reduced. However, it does snow and get bloody cold.
I would suggest looking at the National Trust Scotland site. They have accommodation which is great, but a trifle expensive
And finally, I would echo what others have said- distance does not reflect time. It would take a day to drive from Edinburgh to The Isle of Skye. On a good day.
Oh, don’t be fooled. This is not an easy stroll along a canal tow path. There’s a fair number of hilly stretches, especially alongside Loch Ness where the views are magnificent. The feeling of accomplishment comes from going coast to coast - when you do it with Caledonian Discovery you go from sea lock to sea lock - west coast to east coast.